For some time now, the market has seen an increase in the popularity of beverage machines or dispensers which use single-serve units that need to be inserted in the corresponding sections of the machines which contain the substance from which the beverage is obtained via extraction through the passage of water under pressure.
The single-serve units currently in use are basically of two types. One type of unit is generally called a “capsule” and is basically a unit with rigid walls containing the food substance and that has two bases through which the extraction water passes. The capsules are placed into chambers defined by two bodies, one shaped to receive most of the capsule and a closing body which tightly seals the chamber. The water is introduced into the chamber by traversing the capsule. Thanks to the rigid shape of the capsule, the hydraulic seals of the chamber allow the water to basically traverse the capsule without recirculating the extracted substance through the chamber.
A second type of unit, of a flat shape, is generally called a “pod” and consists of two sections made of thin soft material, pierced, paired in order to define a cavity in which the food substance is placed. The material may be for example paper, or a cloth or a non-woven fabric with filtering properties. The two sections are generally circular and are coupled along their outer edges, defining an outer annular flange. The machines which use pods have two half-shells which are sealed to define a chamber where the pod is placed. Specifically, the annular flange of the pod is squeezed, for sealing, between the opposite surfaces of the half-shells, defined outside the chamber. Due to the pod's soft consistency, the water introduced into the chamber and the resulting beverage basically also reach the walls of the chamber; moreover, the seal obtained in the area of the flange is insufficient and the water and the extracted substance tend to reach the outer limits of the sealing area (that is, the area occupied by the flange) due to the liquid absorption capacity of the material of which the pod is made.
The factors which influence the final quality of the beverage produced with this kind of equipment and units include, among other, the quality of the food substance from which the beverage is extracted, the quantity of substance inside the unit, the quality of the water extracting the beverage, the quantity and the temperature of this water, as well as the pressure and speed with which the water passes through the unit. These factors are linked to each other and the final result depends on how they combine with each other.
The machines currently on the market make it possible to control some of these parameters, such as for example the quantity of beverage to be obtained (for example, a large coffee or a strong coffee), or the water temperature, but are not able to control the parameters depending on the type of substance contained. For example, considering a single-serve unit with a substance for a cold beverage, the user of the machine must already know which command to use in order to obtain cold water to extract the beverage. The machine is not able to tell which type of unit is being used. Another typical example is the case of a single-serve coffee unit for “strong coffee.” The user will have to press the button for “strong coffee” (and will therefore need to know well the machine in order to operate the desired selection). It goes without saying that there are many different options that may occur and hence it would be necessary to provide the user with many different commands, which would make the machine particularly complicated and difficult to use. Instead, machine producers have opted to manufacture machines which are easy to use.
Another problem typical of single-serve beverage units to be used in this type of dispensers is due to the use of units in machines which are not suitable for them. This problem occurs particularly for pods and less for capsules. In fact, the rigid walls of the capsules make it difficult to introduce a capsule which is not suitable for the said machine, as even small size differences would prevent the infusion chamber from closing. The situation is different in the case of pods, as their soft consistency makes it possible to place into the chamber pods with sizes slightly different from those of the pods intended for use with the respective machine; the introduction of a pod which is not suitable for that machine, even if the infusion chambers seems to close, usually leads to bad sealing of the chamber, with resulting loss (in some cases abundantly so) of water or beverage through the seals and soiling the area around the machine.
Another problem linked to the shape of the units is due to the now growing market of “false units,” that is units which are peddled as originals, but which a careful external examination show to instead be counterfeits, with the obvious damage that results for coffee producers. This problem is particularly important in the case of pods, given their low production price.